Sealing tapes unwound from sealing tape rolls are usually used to seal joints such as those between a frame profile of a window or a door and a building wall to seal the joints against drafts and driving rain. Films additionally provided on a lateral surface of the sealing tape increase the impermeability of the tape to water vapor; see, for example, U.S. Pat. No. 4,401,716, US 2010/009118 A1 and US 2010/003465 A1. Because these films, which are applied externally to the sealing tape, suffer from the disadvantage that they can be damaged during the transport or installation of the sealing tape, it is now common practice for films forming a barrier layer to be arranged inside the sealing tape.
Various methods are known for the production of sealing tapes with barrier layers on the inside. These methods involve the introduction of films or similar materials capable of forming a barrier layer into a sealing tape. US 2016/060068 A1, for example, describes a method in which at least two foam strips are provided. One of the side surfaces of one of the foam strips is provided with a film strip and with an adhesive tape strip or an adhesive-like fluid medium. The two foam strips are then brought together in such a way that a foam-barrier layer web is obtained, in which a barrier layer is arranged between adjacent foam strips, the barrier layer being formed by the film strip and the adhesive strip or adhesive-like fluid medium. In this method, it has been found disadvantageous that a considerable amount of effort is required to make available individual foam strips equipped with barrier layer material. The larger the number of barrier layers which the sealing tape is intended to have, the greater this effort.
US 2016/059536 A1 describes an alternative method for the production of sealing tape rolls with an interior barrier layer. In this method, a foam web is produced first. Then a plurality of cuts extending in the longitudinal direction is made in the foam web to form parallel foam strips. Then a film strip and an adhesive tape strip or an adhesive-like fluid medium are introduced into each of the intermediate spaces between two adjacent foam strips produced by the cuts. All of the foam strips are bonded together to produce a foam-barrier layer web, in which the foam strips and the at least one barrier layer alternate. It is sometimes difficult to introduce the barrier layer material reliably into the very narrow intermediate spaces and to ensure that the material is distributed uniformly over the entire thickness of the foam web or of the foam strips. It is possible only with considerable difficulty to check the introduced barrier layer after the material has been introduced. In addition, complicated deflection devices must be provided to introduce a film strip into an intermediate space formed by a cut, for example.